Fifty-fifty chess

Chessclub `Promotie' (`Promotion') in Zoetermeer, the Netherlands has
for many years each year between Christmas and New Years Eve an `Oliebollen'-tournament.
(Oliebollen are a tradition Dutch treat for the end of the year.) In this
tournament, several chess variants are played - some existing ones, but
also several new ones, just invented for the occasion.

One of such variants, described in a booklet called `Bloemlezing Humorschaak',
written by Henk Breugem of SV Promotie, is this variant, called `Fifty-fifty
chess'. The variant is probably invented by Henk Breugem or another member
of Chessclub `Promotie'.

Rules

The rules of orthodox chess are changed in the following way: before one
may mate the king of the opponent, one must first have taken at least eight
pieces of the opponent. (Pawns also count for pieces.) Chess should be
taken care of as usual, even before the opponent has taken eight pieces.

Written by Hans Bodlaender, based on Henk Breughem's booklet.
WWW page created: January 26, 1997.
﻿

Comments

Why is this called Fifty-fifty? Because half the pieces have to be captured before checkmate is permitted. Probably Dutch the standard form is that the appearance of checkmate and plain check is allowed along the way, and the King just cannot be legally captured til 50% of pieces are gone. There then could be a retroactive question that needs clarification.
Or in a stretch just to be witty, mis-spell it Fifty-five, and then the King is the "fifty-fifth," working backwards from 64 (squares), as though notionally every square has or represents a piece, less the other King's space.
A CV subvariant generalizes Fifty-fifty, to draw out of a hat how many pieces have to be captured before checkmate, any number from 6 to 15. Then further subvariant of that one is to "philidor" it and make it an odds game, one side has to capture 6 and the other 10 before permitting mate/checkmate.
The same Breughem made a specific target of 21, http://www.chessvariants.org/winning.dir/blackjack.html.
This CV like the others of the mid-nineties, Falcon, Centennial, Hostage, is about 20 years old now.